Hi, I would like to create a spring inclined with respect to the coordinate system, using NX Nastrain 12.
Solved! Go to Solution.
If GA and GB are non-coincident, the default for both CBUSH and CBUSH1D is uniaxial:
CBUSH Remark 5:
For noncoincident grids, if neither GO or X1, X2, X3 is specified and no CID is specified, then the line AB is the element x-axis, and the y-axis and z-axis are considered undefined. This option is valid only when K1 (or B1) or K4 (or B4) or both are specified on the PBUSH entry (but K2, K3, K5, K6 or B2, B3, B5, B6 are not specified). If K2, K3, K5, or K6 (or B2, B3, B5, or B6) are specified, a fatal message will be issued.
CBUSH1D Remark 1:
For noncoincident grids GA ≠ GB and if CID is blank, the line GA to GB is the element axis.
The issue is that the displacement coordinate system at node 3 is not aligned with the spring direction. In the attached updated models, I've created a cartesian csys rotated 30 degrees so that the X axis of the local csys is aligned with the uniaxial spring direction. I then modified the nodal displacement csys of node 3 to point to the new csys. With this change, both springs have a displacement magnitude of 1.0 in the uniaxial direction.
Enable CSYS Override: If this is off, CID is not written (the condition documented in Remark 1 quoted in my reply above(. If this is on, you select an actual CSYS, which is exported to the input deck and the label of this csys is set as CID on CBUSH1D
Uniaxial: If this is on, the other two Element Orientation inputws are hidden on the dialog and none of the orientation fields (CID on CBUSH1D; CID / GO / X1, X2, X3 on CBUSH) are written to the input deck. This leads to the condition documented in Remark 3 quoted in my reply above.
Enable CSYS Override: If this is on, you select an actual CSYS, which is exported to the input deck and the label of this csys is set as CID on CBUSH/CBUSH1D. X1, X2 and X3 are not written to the input deck.
Specify Vector: This vector sets X1, X2 and X3 on CBUSH. CID is not written to the input deck
Under Spring Damper:
If Offset Definition = GA-GB line, the location input sets S on CBUSH. This is the parametric location (varies between 0.0 and 1.0) along the element X axis.. OCID and S1, S2, S3 are not written to the input deck.
If Offset Definition = Coordinate System, then a coordinate system is selected and Components 1, 2 and 3 are specified. The ID of the selected csys is written to OCID and the components are written to S1, S2 and S3. S is not written to the input deck.